can canyone here help me with this physics problem:(adsbygoogle = window.adsbygoogle || []).push({});

Air moving at 11.0 m/s in a steady winds encounters a windmill of diameter 2.3m and having an efficiency of 27.5 %. The energy generated by the windmill is used to pump water from a well 32.5m deep into a tank 2.30m above the ground. At what rate in liters per minute can water be pumped into the tank?

This is what I have so far:

Ekin = 1/2mv^2

Density for air is: 1.29 kg/m^3

The time for this energy to form is 1 sec.

m = ( a * v * A ) ..... where A is air density and v is velocity, a in this case is area of the windmill, which is pi(diameter/2)^2

Thus

Ekin = 1/2 (a * v * A)

So :

Ekin * 25% = energy generated by the windmill

After that, I'm lost. But I think it has to do something with potential energy.

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# Help : isolated system-conservation of mechnaical energy

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